Though a bit of a setback for Rentrak, which has positioned itself as a rival to Nielsen, media buyers said they would continue to use Rentrak’s data as its measurement services evolve in connection with its work with the MRC.

Rentrak has announced signing deals to provide TV measurement with a large number of local TV stations, an area where Nielsen’s often-criticized service comes under particularly heavy fire.

Most major broadcast and cable networks subscribe to Rentrak as a supplement to Nielsen data, as do the big media buying agencies. WPP, which owns GroupM the largest media buying organization, acquired a stake in Rentrak last year and signed up for Rentrak’s TV measurement services.

“The products were not sufficiently compliant with MRC’s standards,” the MRC said in a statement. The MRC said its work with Rentrak is ongoing and “it is not unusual for complex rating service to not pass the initial audit and have the need to make improvements.”

The MRC added that it “believes that television return-path data from MVPDs, once adjusted and audience-attributed, can be a viable source for audience ratings presenting opportunities for enhanced granularity and stability.”

A Rentrak spokesman said that Rentrak remains committed to the MRC process and is working with the group in a remediation period as it moves on to the next audit. “Rentrak also knows that not passing the first audit is not an unusual position to be in as it is a continual process,” the spokesman said.

The MRC said Rentrak engaged the MRC in 2011. The initial audit was completed in late 2014 and closed in early 2015. The products involved in audit were Rentrak’s TV Essentials and StationView Essentials.